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We are on a journey installing various Lync Server 2013 roles. In today’s step by step, we will setup our 2nd Lync Server Standard Edition pool and then set it up as a Backup Registrar so automatic failover can happen. We will also look at Lync Server 2013’s new failover capabilities that allow full client capability to be restored in the event of a disaster. To use this blog the only other lab you need to have done is Part 1.

Prepare the 2nd Front End Server: Prerequisites

See Lync Server 2013 prerequisites here. Installing your 2nd Lync Pool is much like installing the first. We will go over the steps below briefly, with special notes. But for detailed notes on installing an FE server, just refer to the Part1 blog in this series.

Install Lync Server 2013

Insert Lync Server 2013 CD, and when you see popup below, click Yes

Once the Deployment Wizard appears we are done here for now.

Open Topology Builder to Add Your 2nd Front End Server/Pool

Right Click on “Standard Edition Front End Servers” | New Front End Pool

NOTE: While the topology builder and this blog refer to a Standard Edition Front End Pool, just be aware that a Standard Edition Front End Pool really is just one Front End Server, because there only can be one server in a Standard Edition Pool.

Next | Enter our Backup Front End FQDN (FE02.lab.local) | Next

Check Conferencing, Enterprise Voice. (Note: you will not be able to check CAC because only 1 per Site)

Now instead of screenshots for each screen, we’ll just note what we want to check.

Collocate Mediation = Yes | Next

Enable and Edge Pool = No | Next

let defaults | Next

let Defaults (Note: you need to create this share just like your original share) | Next

After you move a user there is no need to refresh the user list, this is automatically done for you. And, sure enough, the u1@lab.local is now on FE02.lab.local! Great.

Now lets open Lync 2013 client and login using user u1@lab.local that we just enabled on our 2nd Standard Edition Front End Pool/Server (FE02.lab.local). Good, our new pool works!

What Happens when we change Pools During an Active Conversation or Call?

Since we could easily move user(s) to our new Pool/Server with no sweat, now lets get dangerous. Call someone using u1@lab.local and CHANGE POOLS DURING THE CALL. Let’s repeat the steps we just took above, but do it during a live call and see what happens.

Below is a screenshot of what happens if you change pools/servers during a peer to peer call:

The Lync 2013 client will momentarily logout and back in again

During this time (as you see below) the call continues

Sharing continues

Video continues

As noted in the conversation window, functionality is momentarily limited:

Video cannot be started during momentary logout/in

Sharing limited and below items will be interrupted

Polls

whiteboard

Powerpoint

That’ pretty cool, right? Yeah.

Setup a Resilient Pool (aka Associated Backup Pool)

Now let’s setup our 2nd Front End Pool/Server as an Associated backup pool so that if our 1st Front End Pool goes down the clients can automatically failover to the 2nd Front End Pool.

Run the below Powershell commands on your FE01.lab.local to ensure conferencing data is replicated:

Invoke-CSBackupServiceSync –PoolFqdn FE01.lab.local

Invoke-CSBackupServiceSync –PoolFqdn FE02.lab.local

Add DNS SRV Record for Backup Pool/Server

Now lets go into DNS and add a record for our Backup Pool /Server. This SRV record is necessary so that if the first server (FE01.lab.local in our lab) goes down, the client can find the backup Pool/Server.

So let open the DNS server management and add the SRV record. The things that are important:

Make sure all your users (that you want to test resiliency for) are homed on FE01.lab.local. Next, we’ll simulate our FE01.lab.local machine being down by disabling the NIC.

Now around 30 seconds, our client(s) should log out. Sure enough!

Now they will try to login to the backup pool (in this case FE02.lab.local)…

NOTE: We setup our failover to happen in 30seconds. I’ve noticed in my lab the failing Lync clients will logout very near 30 seconds, but it could take several minutes till the clients are able to log back into the Associated Backup Pool/Server (FE02.lab.local). (ie: be fully failed over) I haven’t taken the time to investigate if this is my lowly lab’s performance , or something built into Lync. (if someone knows, please post a comment)

But sure enough, it logged into backup pool! You will notice the Lync 2013 client let’s you know you have some limitations:

Contact List is unavailable

Call Forwarding may not be working

Delegates and Team-Call may not be receiving calls

Limited chat room access

Etc.

Now if we enable the NIC on FE01.lab.local the clients should Failback to FE01.lab.local in 30 seconds. (NOTE: on my lab some clients would failback as soon as 10 seconds.)

Next We Will Take a Look at New Lync Server 2013 Failover Options

Much of what we have discussed in this blog so far is largely the functionality you will find in Lync Server 2010. (I suspect you could use most of the above steps in Lync 2010.) But with Lync Server 2013, the Lync Server administrator can now failover the CMS and the failed pool so that the “Limited Functionality due to outage” is removed. Let’s get started with our failover.

Our first step is to find out where the Active Central Management Database is hosted. To do this we run the PowerShell:

Get-CsService –CentralManagement

As shown below, FE01.lab.local is the PoolFqdn (we will refer to this as $CMS_Pool) of the currently Active CMS.

The next step is to check if the the $CMS_Pool is running Lync Server 2013. You can do this in Topology Builder (in our lab we know it is, but in a live environment we might not) If the $CMS_Pool is running Lync 2013 we can use this PowerShell to see who it’s backup pool is:

Get-CsPoolBackupRelationship –PoolFQDN $CMS_Pool

As shown below we can see the $Backup_Pool is FE02.lab.local

Next we will see if the $CMS_Pool is available right now:

Get-CsManagementStoreReplicationStatus –CentralManagementStoreStatus

Below we have an example how this command will look with the $CMS_Pool available.

Now run the Get-CsManagementStoreReplicationStatus –CentralManagementStoreStatus command again. Note that the command will fail/error out if the $CMS_Pool/FE01.lab.local is not available.

(NOTE: If this is a Ent. Edition server you will need to check which Back End holds the primary CMS using: Get-CsDatabaseMirrorState -DatabaseType CMS -PoolFqdn <Backup_Pool Fqdn> . Read more about this command by Clicking Here. Running this command on Std. Edition will fail. On a Std. Edition server there is only one server so we know which it is. )

Next we will run the command to failover the Central Management Server to our Backup Server:

Hi Matt, Enjoy your work. You have always been very helpful for me in my endeavour to get the most out of Lync. My question which I think I know the answer for is. "Can I setup automatic failover for Lync 2013 SE?" or does there have to be a manual element. I knwo you need to have SQL mirroring and witnesses setup for automation. Does SE only allow SQL express or can I move my DB's to a full SQL box and setup Mirroring and failover ?

Matt, used this post to troubleshoot part of our 2010 to 2013 migration. Our Topology already had the 2013 backup registrar setup, however when we migrated the Central Management store from 2010 to the 2013 pool the backup 2013 server wouldn't replicate or report a "happy" status in CSCP.Had to re-run the deployment on the 2013 Backup, delete the CMS database on the 2013 backup and then run the powershell to re-create the database and reboot and then everyone was happy.

Matt, hello. Can you help me? When i do "Invoke-CSBackupServiceSync –PoolFqdn FE02.lab.local" (on FE01.lab.local), i get error The HTTP request is unauthorized with client authentication scheme 'Ntlm'. The authentication header received from the server was 'Negotiate, oXsweaADCgEBonIEcGBuBgkqhkiG9xIBAgIDAH5fMF2gAwIBBaEDAgEepBEYDzIwMTMwNjEyMTYxMzMwWqUFAgMJkkKmAwIBKakZGxdDRU5URVIuQVNTT1JUSS5LT01JLkNPTaoXMBWgAwIBAaEOMAwbCmx5bmMyMDEzMiQ=".'Sync dont work...

Hi All,Can someone tell me if you always have to failover the CMS database manually (commandline) when there is an outage of the primary pool server ? Isn't there a way to do this automtically ?Thank you

Thank you for the great guide! Any idea why I can see messages from users on server A in pool A, but I cannot respond and get an error that user from server A is offline, even though they are not and I see it OK. I am in server B/pool B. Thanks!!

What about removing all of this? I am about to decom my DR and voice resiliency config form the topology and want to know what ramifications (if any) it will have on production and users. I know the setup of this requires to run the deployment wizard on each FE server in the pool, but what needs to be done to remove it?

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About Me

Matthew M. Landis has various industry certifications: Microsoft Certified Systems Engineer, Microsoft Certified Database Administrator, Microsoft Office Certified Expert, Microsoft Certified Dynamics, Network+ and A+.
In 1995 Matt started Landis Computer which has been providing IT services to small businesses for 14 years and is now a 11 person Microsoft Gold Certified Partner. Matt has over 14 years of field experience implementing Windows Server, Microsoft & Dynamics ERP solutions in small business environments.
Matt is very active in the Windows based IP PBX community: He was a 3CX Valued Professional from 2008-2010 and has co-authored a book on Windows communication software "3CX IP PBX Tutorial". He is pbxnsip Certified, he has contributed thousands of posts to the 3CX community forum and he writes the monthly Windows PBX Report e-newsletter for VARS and administrators. His company, Landis Computer, was the first company in the USA to be designated a 3CX Premium Partner.
When not working and when a chance affords Matt likes to travel internationally with his wife Rosalyn and is very involved in his church.